Total participant = 9180
Of the total participants, 4/9 had two parent2 with blue eyes
$$\frac{4}{9}\cdot9180=4080$$
remaining participants = 9180 - 4080 = 5100
Of the remaining participants, 8/17 had one parent with blue eyes
$$\frac{8}{17}\cdot5100=2400$$
Participant with two blue-eyed parent and one blue-eyed parent had at least one blue-eyed parent; so their total = 4080 + 2400
= 6480
Answer = option D